There is known a differential transmission system adapted to transmit a differential signal pair, comprising signals having opposite phases, in two signal lines forming a pair. Since the differential transmission system has a feature that a high data transfer rate can be achieved, it has recently been put to practical use in various fields. One example of a connector that can be used for that purpose is disclosed in JP-A-2010-287560 (hereinafter referred to as “Patent Document 1”).
The connector of Patent Document 1 will be described with reference to FIG. 6 showing a terminal array 1 of the connector. The illustrated terminal array 1 comprises a number of terminals of the same shape which are arranged at regular intervals in a row. These terminals are divided into a plurality of ground terminals 2 and a plurality of pairs of signal terminals 3. The signal terminals 3 of each pair are disposed between two adjacent ones of the ground terminals 2. According to this configuration, since each ground terminal 2 is disposed between the adjacent pairs of signal terminals 3, crosstalk between the pairs of signal terminals 3 can be expected to be reduced.
However, as described above, in the connector of Patent Document 1, a number of the terminals of the same shape are arranged at regular intervals in a row. Thus, there arises a problem if the array pitch of the terminals is narrowed to miniaturize the connector. That is, if the array pitch of the terminals is narrowed, the capacitance between the terminals increases so that the impedance decreases, thus leading to degradation of the transmission characteristics. Therefore, the connector of Patent Document 1 is not suitable for application as a Type C Mini HDMI (High Definition Multimedia Interface) connector in which the pitch of a terminal array is narrowed to about 0.4 mm.